In a two-wheeled motor vehicle, a front-wheel brake is operated by a right brake lever, and a rear-wheel brake is operated by a right brake pedal. If braking force is not appropriately balanced between the front and rear wheels, the two-wheeled motor vehicle may be fallen down. Thus, a driver needs to operate the right brake lever and the right brake pedal so as to appropriately keep balance of braking force between the front and rear wheels. Furthermore, for example, patent documents 1, 2 and 3 propose front-and-rear-wheel-interlocked braking systems respectively, in which balance of braking force between the front and rear wheels is appropriately controlled regardless of how a driver operates the lever and the pedal.
Each of the front-and-rear-wheel-interlocked braking systems has an antilock braking system (ABS), and has a front-wheel brake circuit and a rear-wheel brake circuit, where the respective brake circuits operate in an interlocked manner depending on braking operation, so that balance of braking force between the front and rear wheels is automatically appropriately controlled.
In the invention of the application, while being described later, backflow check means such as a check valve is provided in a pipeline for connecting between two wheel cylinders. However, patent documents 4 and 5 disclose systems, in each of which a check valve is provided in a pipeline for connecting between two wheel cylinders.
Patent document 1: JP-A-2000-719.63
Patent document 2: JP-A-2005-212680
Patent document 3: JP-A-2003-25978
Patent document 4: JP-A-6-211120
Patent document 5: JP-A-5-310114